Catalytic desulfurization of residual oil through partial oxidation in supercritical water

Catalytic desulfurization of a model sulfur-containing compound benzothiophene (BT) through partial oxidation in supercritical water (SCW) was investigated in a bomb reactor at 623–723 K and 30–40 MPa over sulfided CoMo/γ-Al2O3. Vacuum residuum was used to confirm the desulfurization rate and efficiency, and the desulfurization mechanism of vacuum residuum was determined by the pyrolysis temperature (TR) of the vacuum residuum (VR). For T > TR, obvious reduction of sulfides up to 67% was obtained. The thermodynamic equilibrium of in situ H2 generation was a controlling factor of the desulfurization pathway.